Lux to Lumens Calculator

Easily convert lux to lumens for better lighting design. Essential for interior designers and lighting professionals.

Enter Illuminance in lux:
Select area unit type:
Enter spherical radius:
Or enter surface area:
Luminous flux result in lumens:

When it comes to lighting, two terms frequently come up: Lux and Lumens. Understanding these terms is essential for creating well-lit spaces. Lux refers to the amount of light per unit area, while Lumens measure the total amount of visible light emitted by a source. Both Lux and Lumens play crucial roles in determining the quality and effectiveness of lighting solutions.

Lux and Lumens are often confused, but they represent distinct aspects of lighting. While Lux measures the intensity of light falling on a surface, Lumens quantify the total output of light from a source. In simpler terms, Lux indicates how bright the light appears, whereas Lumens signify the total brightness of the light source itself.

Lux to Lumens Calculation Formula

To calculate Lumens from Lux, you need to know the area over which the Lux measurement is taken and the beam angle of the light source. The formula for Lux to Lumens conversion is:

Lumens = Lux × Area (in square meters) ÷ Beam Angle (in steradians)

Let's break down the formula:


Suppose you have a Lux measurement of 500 Lux taken at a distance where the surface area is 10 square meters. The light source has a beam angle of 0.5 steradians.

Using the formula:

Lumens = 500 Lux × 10 square meters ÷ 0.5 steradians

Lumens = 5000 lumens

So, in this example, the light source emits 5000 lumens of light.

Frequently Asked Questions

Lux to Lumens conversion is a crucial process in lighting design and evaluation. It helps determine the total brightness output of a light source based on the intensity of light falling on a surface. This conversion is essential for ensuring that lighting setups meet the required standards for visibility, comfort, and energy efficiency.

Whether designing lighting for indoor spaces like offices and homes or outdoor environments such as streets and stadiums, Lux to Lumens conversion plays a vital role in achieving optimal lighting solutions.

Yes, Lux to Lumens conversion can vary depending on various factors, including the type of light source, beam angle, and surface reflectance. Different types of lighting, such as incandescent, fluorescent, LED, and natural light, emit light differently, affecting the Lux to Lumens conversion process.

Additionally, factors like the distance between the light source and the surface being illuminated and the presence of obstructions or reflective surfaces can influence the conversion ratio. Therefore, it's essential to consider these variables when performing Lux to Lumens calculations for different lighting setups.

No, Lux and Lumens are distinct measurements that serve different purposes in lighting. Lux measures the intensity of light per unit area, typically expressed as lumens per square meter (lm/m²). It indicates how bright the light appears to an observer at a specific point. On the other hand, Lumens quantify the total amount of visible light emitted by a source, regardless of the area it illuminates.

While Lux provides information about the brightness of light falling on a surface, Lumens describe the total brightness output of the light source itself. Therefore, Lux and Lumens are not interchangeable and are used in conjunction to assess and design lighting systems effectively.

Lux to Lumens calculators are versatile tools that can be used for various lighting setups, including indoor, outdoor, residential, commercial, and industrial applications. However, the suitability of a Lux to Lumens calculator depends on several factors, such as the accuracy of its calculations, the range of input parameters supported, and the specific requirements of the lighting project.

While most Lux to Lumens calculators are designed to accommodate a wide range of lighting scenarios, users should ensure that the calculator they choose aligns with their needs and preferences.